Urban legend says that Mona Lisa's eyes will follow you as you move around the room. This is known as the "Mona Lisa effect." For fun, I recently programmed an interactive digital portrait that brings this phenomenon to life through your browser and webcam. The general idea is as follows: first, we must generate a sequence of images of Mona Lisa's head, with eyes gazing from the left to right. From this pool, we'll continuously select and display a single frame in real-time based on the viewer's location. In this post, I'll walk through the specifics of the project's technical design and implementation.

Cat filters and rock star sunglasses are just the tip of the iceberg in today's ocean of face-based augmented reality (AR) mobile applications. Such effects are however compute-hungry, and today's users want their novelty images to pop up on their smartphone screens without delay. Luckily for us, Google fully appreciates the need for speed. Google researchers have introduced a new face detection framework called BlazeFace, adapted from the Single Shot Multibox Detector (SSD) framework and optimized for inference on mobile GPUs. The lightweight face detector runs at an impressive speed of 200-1000 FPS on flagship smartphones.